There has been conventionally known an energy storage device electrode for use in electric double-layer capacitors, lithium ion capacitors, lithium ion batteries, or other similar devices which includes collector foil and an electrode layer applied to a surface of the collector foil and which lowers, in order to lower internal resistance, the contact resistance between the collector foil and the electrode layer by pressing some of electrode particles of the electrode layer into the surface of the collector foil (see, for example, Patent Literature 1).